解题方法
1 . 绿色已成为当今世界主题,绿色动力已成为时代的驱动力,绿色能源是未来新能源行业的主导.某汽车公司顺应时代潮流,最新研发了一款新能源汽车,并在出厂前对该批次汽车随机抽取100辆进行了单次最大续航里程(理论上是指新能源汽车所装载的燃料或电池所能够提供给车行驶的最远里程)的测试.现对测试数据进行分析,得到如图所示的频率分布
(同一组中的数据用该组区间的中点值代表);
(2)若单次最大续航里程在
到
的汽车为“
类汽车”,以抽样检测的频率作为实际情况的概率,从该汽车公司最新研发的新能源汽车中随机抽取10辆,设这10辆汽车中为“
类汽车”的数量为
,求
.
(3)某汽车销售公司为推广此款新能源汽车,现面向意向客户推出“玩游戏,送大奖”活动,客户可根据拋掷硬币的结果,操控微型遥控车在方格图上行进,若遥控车最终停在“胜利大本营”,则可获得购车优惠券.已知硬币出现正、反面的概率都是
,方格图上标有第0格、第1格、第2格、
、第30格.遥控车开始在第0格,客户每掷一次硬币,遥控车向前移动一次,若掷出正面,遥控车向前移动一格(从
到
),若掷出反面,遥控车向前移动两格(从
到
),直到遥控车移到第29格(胜利大本营)或第30格(失败大本营)时,游戏结束.已知遥控车在第0格的概率为
,设遥控车移到第
格的概率为
,试证明:数列
是等比数列,并解释此方案能否成功吸引顾客购买该款新能源汽车?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c85481cd7e94130ef3aa05b4a39e79cd.png)
(2)若单次最大续航里程在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3bcb74e7cb4235102c7b8eda1f504f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ad9a2c58a224e801450544406635596.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b0bd6753e573bfbe6742d08ef6dfe83.png)
(3)某汽车销售公司为推广此款新能源汽车,现面向意向客户推出“玩游戏,送大奖”活动,客户可根据拋掷硬币的结果,操控微型遥控车在方格图上行进,若遥控车最终停在“胜利大本营”,则可获得购车优惠券.已知硬币出现正、反面的概率都是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa5e9bd516f6282483b92cfe6074623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b00f4eb7f1bd2ccefbabf0c1dfa8f69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4792fd59c4ca11ff03dc32e367c3983f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cceb0153024c9beaf92e76b633d239b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a923a83a659f0a544954f73a29241e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45c53fb3df93e2c2bb9f3140b07c92fb.png)
您最近一年使用:0次
2 . 已知抛物线
的焦点为
,过
且倾斜角为
的直线
与
交于
,
两点.直线
,
与
相切,切点分别为
,
,
,
与
轴的交点分别为
,
两点,且
.
(1)求
的方程;
(2)若点
为
上一动点(与
,
及坐标原点均不重合),直线
与
相切,切点为
,
与
,
的交点分别为
,
.记
,
的面积分别为
,
.
①请问:以
,
为直径的圆是否过定点?若过定点,求出该定点坐标;若不过定点,请说明理由;
②证明:
为定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82ea1be9b9b6bb12afa7e1ce703d1603.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037fb348109dc2063a268b10eb925a57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/889c77ab62cad9151cfe679b8181d445.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fce9427c9b17e4d3cda0c3ff3e2e14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/029ad83f1a3262048cba0e650b63e929.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a019625b21ba728a67a3f6437709ace4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
①请问:以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
②证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/235f0a6fb218d28383e6f27f2df1f50f.png)
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3 . “南澳牡蛎”是我国地理标志产品,产量高、肉质肥、营养好,素有“海洋牛奶精品”的美誉.2024年该基地考虑增加人工投入,现有以往的人工投入增量x(人)与年收益增量y(万元)的数据如下:
该基地为了预测人工投入增量为16人时的年收益增量,建立了y与x的两个回归模型:
模型①:由最小二乘公式可求得y与x的线性回归方程:
;
模型②:由散点图的样本点分布,可以认为样本点集中在曲线:
的附近,对人工投入增量x做变换,令
,则
,且有
,
,
,
.
(ii)根据下列表格中的数据,比较两种模型的决定系数
,并选择拟合精度更高、更可靠的模型,预测人工投入增量为16人时的年收益增量.
(2)根据养殖规模与以往的养殖经验,产自某南澳牡蛎养殖基地的单个“南澳牡蛎”质量(克)在正常环境下服从正态分布
.购买10只该基地的“南澳牡蛎”,会买到质量小于20g的牡蛎的可能性有多大?
附:若随机变量
,则
,
;
样本
的最小二乘估计公式为:
,
,
.
人工投入增量x(人) | 2 | 3 | 4 | 6 | 8 | 10 | 13 |
年收益增量y(万元) | 13 | 22 | 31 | 42 | 50 | 56 | 58 |
模型①:由最小二乘公式可求得y与x的线性回归方程:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84bc4486ffeb321242a9982309efff8c.png)
模型②:由散点图的样本点分布,可以认为样本点集中在曲线:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b328c19977481e5ea0ca585af1ef4394.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b90ca3b73b0040365d9f55be51433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a8ee45ed2358f5d5ad60eaf4c8830da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c3af5d6a45c01b7d0c7c537506e1c56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c4fac1fe3facd6cec349abafe3ae59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd1aec923d21f9cdf93c257769eca972.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79728a92965ea4df0a12de9878245297.png)
(ii)根据下列表格中的数据,比较两种模型的决定系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
回归模型 | 模型① | 模型② |
回归方程 | ![]() | ![]() |
![]() | 182.4 | 79.2 |
(2)根据养殖规模与以往的养殖经验,产自某南澳牡蛎养殖基地的单个“南澳牡蛎”质量(克)在正常环境下服从正态分布
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b855415af8163cef49c0706e3c0528b.png)
附:若随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e188b5f28f5dc86364cb18c11f8d4702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94c741455594dbc5293c436d8d2c0275.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eabdfcbc03a1d0b223555af8dbf4315.png)
样本
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/539241dbd325e8aef033e0a89ff60125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853e9ba2d135b2d324679c0f4110149a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ebff20f21ae41fd8d1f1e3145895842.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f763c9590d5ca681acf466e4c6d7fa2.png)
您最近一年使用:0次
解题方法
4 . 一个不透明的袋子中装有大小、质地相同的40个小球,其中10个红球,10个黄球,20个绿球,依次随机抽取小球,每次只取1个小球,完成下列问题:
(1)若取出的小球不再放回,
①求最后取完的小球是黄球的概率;
②求红球比其余两种颜色小球更早取完的概率;
③设随机变量
为最后一个红球被取出时所需的取球次数,求
;
(2)若取出的小球又放回袋中,直到取到红球就停止取球,且最多取
次球,设随机变量
为取球次数,证明:
.
(1)若取出的小球不再放回,
①求最后取完的小球是黄球的概率;
②求红球比其余两种颜色小球更早取完的概率;
③设随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf3baba074e8aeb6f3ea117865bbd1b.png)
(2)若取出的小球又放回袋中,直到取到红球就停止取球,且最多取
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d217815119d30cc42255b88b89238022.png)
您最近一年使用:0次
名校
解题方法
5 . 已知抛物线
的焦点为F,O为坐标原点,抛物线C上不同两点A,B同时满足下列三个条件中的两个:①
;②
;③直线AB的方程为
.
(1)请分析说明A,B满足的是哪两个条件?并求抛物线C的标准方程;
(2)若直线
经过点
,且与(1)的抛物线C交于A,B两点,
,若
,求
的值;
(3)点A,B,E为(1)中抛物线C上的不同三点,分别过点A,B,E作抛物线C的三条切线,且三条切线两两相交于M,N,P,求证:
的外接圆过焦点F.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82ea1be9b9b6bb12afa7e1ce703d1603.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5990425fae355d2ba6a8ad45e0dab616.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd73cb091ac6b2acb4c744744a9d166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a68831f427cd565ac3cc341024c9a422.png)
(1)请分析说明A,B满足的是哪两个条件?并求抛物线C的标准方程;
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d8a5982a53874dd3e97d9af6d7942ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fbb6cae4ac201f350e9856544320303.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/687a8b9b8bdaca532100e41cb11d331b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0be44077d42cfffece905b1af13e000.png)
(3)点A,B,E为(1)中抛物线C上的不同三点,分别过点A,B,E作抛物线C的三条切线,且三条切线两两相交于M,N,P,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23b488f961d9fde37feb7f5c497c0d9.png)
您最近一年使用:0次
解题方法
6 . 已知抛物线
,动直线
与抛物线
交于
,
两点,分别过点
、点
作抛物线
的切线
和
,直线
与
轴交于点
,直线
与
轴交于点
,
和
相交于点
.当点
为
时,
的外接圆的面积是
.
(1)求抛物线
的方程;
(2)若直线
的方程是
,点
是抛物线
上在
,
两点之间的动点(异于点
,
),求
的取值范围;
(3)设
为抛物线
的焦点,证明:若
恒成立,则直线
过定点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bf92a1ba410263d4f68b7e0432b19aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf5f0df2579e567038baa206cb0b016f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed283a253b61df01f2a1cdc0cd8003f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20b3a91ccf6028608cd03df7072f6536.png)
(1)求抛物线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/912bae66a2b7cc1caa4cd0333796ec41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59880e470359d8e9faf6ae5ce155cf2a.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32a07da1731feb22da90850241b3580f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
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名校
7 . 已知抛物线
的焦点为F,过点
的直线l与
交于A、B两点.设
在点A、B处的切线分别为
,
,
与x轴交于点M,
与x轴交于点N,设
与
的交点为P.
的斜率,并证明
;
(2)证明:点P必在直线
上;
(3)若P、M、N、T四点共圆,求点P的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/179234a7f5454002d6519079a5ff7972.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4244ff1376012b8dd673587e9ffdffef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14b5aed438b6ff97ebcb449fc80fa431.png)
(2)证明:点P必在直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e6e15daf7b14dbff32c390f4984dcfb.png)
(3)若P、M、N、T四点共圆,求点P的坐标.
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8 . 第二十五届中国国际高新技术成果交易会(简称“高交会”)在深圳闭幕.会展展出了国产全球首架电动垂直起降载人飞碟.观察它的外观造型,我们会被其优美的曲线折服.现代产品外观特别讲究线条感,为此我们需要刻画曲线的弯曲程度.考察如图所示的光滑曲线
上的曲线段
,其弧长为
,当动点从
沿曲线段
运动到
点时,
点的切线
也随着转动到
点的切线
,记这两条切线之间的夹角为
(它等于
的倾斜角与
的倾斜角之差).显然,当弧长固定时,夹角越大,曲线的弯曲程度就越大;当夹角固定时,弧长越小则弯曲程度越大,因此可以定义
为曲线段
的平均曲率;显然当
越接近
,即
越小,
就越能精确刻画曲线
在点
处的弯曲程度,因此定义
(若极限存在)为曲线
在点
处的曲率.(其中
,
分别表示
在点
处的一阶、二阶导数)
的焦点到准线的距离为3,则在该抛物线上点
处的曲率是多少?
(2)若函数
,不等式
对于
恒成立,求
的取值范围;
(3)若动点
的切线沿曲线
运动至点
处的切线,点
的切线与
轴的交点为
.若
,
,
是数列
的前
项和,证明
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d0dd437ad522066cc7d4b7d208e2866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/505d83f4d34a8cd385577a6ce93a4b11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aea61ddc41f927684c6dfaacdd7f8e0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0636a11a086df66133bd50e43481a546.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/427eceadd7bb569ff140ea73d650db1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0636a11a086df66133bd50e43481a546.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aea61ddc41f927684c6dfaacdd7f8e0a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/952bd235a906f77d227dfcfe1cbea780.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/505d83f4d34a8cd385577a6ce93a4b11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf3834d7ec7531f3c3c0ce9b286f7a49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e313d2b28b6d3d6273346e8f9bb78c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b4d2174f411d9db6ab7b2aea47818cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc2b6c6aec8cfad1ce0277d6db9759c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0afb80007983e5b99dcdeebf87d18ff4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8516f71467b419293fa27df70bdaed74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8ad52c0008b852946f7e316474e396d.png)
(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd589f01fd5de86d37e197e022f9dc36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/692a685d89c02da9bab03b7adbd66adc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aedc1c8a16e306bcd6e5154f9ed6dfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/074c228ffc7b1e306f8410afe7bc4b5c.png)
(3)若动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d637a9d76ce3058a0e9b561c832d41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cac935140541b5e1ba7d7dfffdd8325.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c3cbcc09d6f5004f2509aad50eef40f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c4223bd6ee8f82d59d244371fbcddc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e858cf44005397a29962fda98a020d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3819480e1e624208f729ad8653e4f24f.png)
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解题方法
9 . 已知函数
,角A为△ABC的内角,且
.
(2)如图,若角A为锐角,
,且△ABC的面积S为
,点E、F为边AB上的三等分点,点D为边AC的中点,连接DF和EC交于点M,求线段AM的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c2a82f4820d3ffdd52f152c69a70872.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbacffbd6184d83356dc34290522529.png)
(2)如图,若角A为锐角,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efc6e4b936d7a800e839a30c3839574d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7cb903441d8e6b4448c3d5d7959d9d7.png)
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解题方法
10 . 假设甲同学每次投篮命中的概率均为
.
(1)若甲同学投篮4次,求恰好投中2次的概率.
(2)甲同学现有4次投篮机会,若连续投中2次,即停止投篮,否则投篮4次,求投篮次数
的概率分布列及数学期望.
(3)提高投篮命中率,甲学决定参加投篮训练,训练计划如下:先投
个球,若这
个球都投进,则训练结束,否则额外再投
个.试问
为何值时,该同学投篮次数的期望值最大?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
(1)若甲同学投篮4次,求恰好投中2次的概率.
(2)甲同学现有4次投篮机会,若连续投中2次,即停止投篮,否则投篮4次,求投篮次数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(3)提高投篮命中率,甲学决定参加投篮训练,训练计划如下:先投
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f174e6fc40d685bb037f909967634f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c733a209a0091d418d8f14b7fba88dbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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